"Invalid request" when sending badges to backpack

Requirements 2 different Badgr.io US accounts Outgoing server configured (mailcacher or similar) ngrok or similar (for having a public URL in your Moodle instance).   Setup Login as admin. Go to "Site administration / Badges / Badges settings" and set: Badge issuer name: "my_moodle" (or any other value you consider) Badge issuer email address: email user for a Badgr.io (US) account. Go to "Site administration / Badges / Manage backpacks", edit https://badgr.io and add the credentials (email and password), for a valid Badbr.io account. Go to "Site administration / Badges / Backpack settings" and confirm the "Active external backpack" is set to "http://badgr.io". Create a badge and award it to some users.   Testing instructions Login as some of the users awarded with the badge. Go to "Preferences / Badges / Backpack settings". Connect to the backpack using the second Badgr.io account. Open the verification email and open the URL to validate the account. Confirm status is set to Connected. Go to the user profile, open the badge and click over "Add to backpack" button. Confirm the message " Added badge to backpack " is displayed. Access to  https://badgr.io  using this user credentials and confirm the badge is displayed (sometimes it might take a few minutes).